Water-feed-control system for boilers



April 24, 1928. 1,667,057

- 'l. E. SMITH WATER FEED CONTROL S-YSTEI FOR BOILERS filed June 20, 1927 3 Sheets-Sheet 1 F a 1 I 37 INVENTOR 2 w .Izwz Eus'mifih 30 31 ATTORNEY April 24, 1928.

- I. E. SMITH WATER FEED CONTROL SYSTEM FOR BOILERS Filed J ne 20, 1927 a Sheets-Sheet 2 INVENTOR Ira, E.Smi12 BY QM SZQAMML ATTORN EY April24, 1928. 1,667,057

I. E. SMITH WATER FEED CONTROL SYSTEM FOR BOILERS Filed June 20, 1927 3 Sheets-Shee 3 INVENTOR Fa ESmllih ATTO R N EY patented Apr. 24, 192.

IRA E. SMITH,'OF STOCKTON, CALIFORNIA.

WATER-FEED-CONTBOL SYSTEM FOR BOILERS.

Application filed June 20, 1927. Serial No. 199,990.

This invention relates to systems for feeding water into steam boilers as'the supply of water. in the boiler becomes depleted by the generation and consumption of steam; my principal object being to provide an apparatus for the purpose which comprises an electric switch, a pressure actuated unit associated therewith, and a water feed control valve or other device operated by the switch, so arranged and connected to the boiler that as the steam is generated and consumed and the water level lowered the switch will be automatically closed and the water caused to enter the boiler; and when the normal height of water is reached in the boiler the switch will be automatically opened, causing the inflow of water to the boiler to cease.

The apparatus requires no attention and will work constantly and within a very close range so that there is no danger of the water in the boiler ever dropping to such 'a level as to become dangerous.

A further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly effective for the purpose for whichit is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings similar characters of reference indicate corresponding parts in the several views.

Fig. 1 is a side elevation of the apparatus shown in connection with an ordinary form of stationary steam boiler.

Fig. 2 is an enlarged side elevation partly in section of the control mechanism showing the parts in their normal positions and with the switch opened.

Fig. 3 is a sid elevation of the control mechanism showing the switch closed.

Fig. 4 is a side elevat1on of the water;

feed pipe valve control mechanism.

Referring now more particularly to the characters of reference on the drawings, the numeral 1 denotes a steam boiler of ordinary character associated With which is the usual water column 2 which is connectedto the steam space of the boiler by a top pipe 3 and with the water space of the boiler by a bottom ipe 4. The normal water level line in the oiler is indicated at W, the water ing of the vessel.

of course bein'g the same level in the column 2. 5 denotes a water feed pipe leading to the boller from any suitable source of supply and under sufiicient pressure for the purpose.

My improved water feed control structure comprises an electric switch preferably of the mercury contact type which consists of a mercury tube 6 into one end of which a pair of separated contacts 7 project. This tube is supported intermediate its ends for longitudinal rocking movement by a bracket 8 pivoted in a casing 9. An arm 10.projectin horizontally from the bracket is connecte by a link 11 to a horizontal lever 12 which is pivoted intermediate its ends in the casing and projects outwardly'from one side thereof. Inside the casing a spring 13 bearsdown on the lever, these parts being arranged so that when the spring is free to act the tube will be tilted so that the mercury will flow toward the contacts and will engage the same.

Secured to the outer end of the lever is a hollow vessel 14: whose weight when empty is not suflicientto overcome the pressure of the 1 spring 13 but which will overcome such pressure when full of water. Mounted on top of the vessel is a relief valve 15 of standard form which is closed either by heat acting on a diaphragm 16 and causing a float 17 to rise (said float having a valve member 18) or by water acting directly on the float independently of the diaphragm action.

Between the relief valve and the vessel 14 a pipe line 19 is connected which extends downwardly to a connection with the column 2 just below the water level line W. From the bottom of the container 14 a pipe line 20 extends to a connection with the" column 2 at any point below the connection of the pipe 19 therewith. Portions of both pipe lines adjacent the vessel 14 are made of flexible tubing as shown at 21 so as not to interfere with the necessary limited vertical tilt- This apparatus is set some distance above the boiler so that the water in the vessel will tend to flow from the same by gravity.

Mounted in the casing 9 under the lever 12 is another lever 22 which is pivoted inter mediate its ends in the casing. At one end a spring 23 acts on the lever 22 to ralse said end, the other end being engaged by a head gravit 24 provided in connection with a diaphragm .25 which is arranged to be expanded by steam, so that the head 24 will be raised.

A rigid steam pipe 26 (also serving to support the casing) is connected to said diaphragm and extends thence to a connection with the steam pipe 3. An upstanding stop lug 27 on the lever 22 between the pivot thereof and the spring 23 normally bears against the under face of the lever 12. The strength of the spring 23 is suflicient to overcome the action of the spring 13 when the vessel 14 is empty so as to maintain the adjacent end of the lever 12 raised and hold the switch in its open position. When the diaphragm is expanding by steam however the adjacent end of the lever 22 is raised, lowering the opposite end thereof and the stop 27 against the resistance of the spring 23 and permitting the lever 12 to drop if the conditions are such that this 'action will take place.

The closing of the switch controls the operation of a water feed control device, and while various mechanisms may be used for this purpose, in the present instance I have shown this device as being a valve 29 in the water line 5. The stem 30 of this valve is normally held in closed position by a vspring 31, said stem being connected to an arm 32 which is mounted in connection with the pivoted armature 33 of a magnet 34 which is supported in fixed relation to the pipe and valve by a bracket 35 or the like.

These parts are disposed so that when the valve isclosed the armature is spaced from the core of the magnet, the energizing of the latter drawing said armature theretoward and causing the valve to 'be opened, thereby allowing the water under pressure in said pipe to pass by the valve and enter the boiler. Wires 36 from the main power lines 37 to the magnet have the. switch contacts 7 interposed therein, as .illustrated diagrammatically in Fig. '1.

In operation assuming the water-in the boiler to be. at the proper level and cold, there will be no water in the vessel 14, since when there is'no steam pressure in the boiler the water will drain from the vessel by The contacts 7 are therefore open and al the parts of the apparatus are in the positions shown in Fig- 2.

As soon as steam is raised in the boiler, while the water therein. is still above the level of the connection of the pipe 19 with the column 2 (which is the equivalent of the boiler), water will be forced into the vessel 14.- and held therein by such steam pressure and its weight will be added to that of the vessel 'itselfovercoming the spring 13. 4 At the same time the'steam expands the diaphragm 25 causing thesto from the lever 12 and sai stop will remain in this position as long as there is any steam 27 to drop away position owing to the weight of the water in the vessel. As soon as the pipe 19 at the boiler becomes uncovered by the lowering of the water in said boiler, the steam will enter said pipe, assin into the top of the vessel, and will rive t e water out of said vessel through the bottom ipe 20 and back into the boiler. The vessel 14 being thus relieved of its weight of water, the spring 13 is free to function and will therefore lower the adjacentportion of the lever 12 so as to tilt the mercury tube to a contact closing position, as shown in Fig. 3. This energizes the magnet 34, causing the water feed valve to be 0 ened, as previously explained. Tl fe water in the boiler therefore rises until the pipe 19 becomes closed by said water, when the flow of steam to the vessel 14 will be cut off, causing whatever steam is still in the vessel to condense. This permits the vessel to again refill with water due to the pressure of the live steam thereon at the boiler end of the pipe 19. As soon as the vessel is full of water its weight causes the lever 12 to be tilted in the opposite direction, opening the switch and causing the feed of water to be discontinued.

These movements take place intermittently as long as water is being used from the boiler and steam is being generated. As soon as the steam generation ceases the diaphragm 25 returns to its normal position, causing the spring 23 to act and raise the stop 27 against t lelever 12, preventing the latter from being depressed to a switch closing position-until steam is again generated, and regardless of the empty or full condition of the vessel 14. The relief valve 15'ser'ves an important purpose, and is essential in making the device fully automatic in action. When the The lever 12 however boiler and system are relatively cold, and

gravity. When steam is-againgenerated in the boiler and the water is forced up into the vessel, the 0 'en valve will allow the air to escape and t e-water to take its place.

When the level of the water in the boiler drops, permitting steam to enter the vessel and expel the Water, the heat of the steam -acts t'o'expand the diaphragm 16 andhold the float in a valve-closing position, even if said diaphragm is not already expanded by g" I the heat of the water.

'From the foregoin description it will be readily seen that, I ave fiplroduced such a device as substantiall in] s the invention as set orth herein.

While this specification sets forth in de- 5 the objects of i tail the present and preferred construction by the closing of said switch, 2.

the invention, as defined by the appende claims.

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is:

LA water-feed control system for a steam boiler including a normally open electric switch, a water feed device controlled rockabl lever, means between the lever and switch for causing the latter to be opened when the in one direction and vice versa, means acting on said lever tending to tilt it in a switch closing direction, steam released stop means normally preventing the lever from thus being tilted, a vessel supported by the outer end of the lever and tending to tilt the lever in a switch opening direction; the weight of said vessel when empty being insuflicient to overcome sai first named tilting means but causing said first named means to be overcome when the vessel is full lever is tilted of water, means causing said vessel to be filled with water when the water in the-boiler is at a predetermined level, and means causing the vessel to be emptied 0 such water when the water in the boiler drops below such level.

2. A water-feed control steam boiler including a normally open electric switch, a water feed device controlle by the closing of said switch, a rockable lever, means between the lever and switch for causing the latter to be opened when the lever is tilted in one direction and vice versa, means acting on said lever tending to system for a tilt it in a switch closing direction, steam.

released stop means normally preventing the lever fromthus being tilted, a vessel supported by the outer end tending to tilt the lever in direction; the weight of empty being insufiicient to overcome sai first named'tilting means but causing said of the lever an a switch opening said vessel when first named means to be overcome whenthe d bottom of the vessel to lever from tiltin in d high temperature in the vessel.

a pipe from the top vessel is full of water,

the

of said vessel to the boiler just below full-water level therein,

the boiler ata point below the connection of the first named pipe therewith.

3. A- water-feed control system for a steam boiler including a normally open electric switch, a water feed device controlled by the closing of said switch, a rockable lever, means between the lever and switch for causing the latter to be opened when the lever is tilted in one direction and vice versa, means acting on said lever tending to tilt it in a switch closing direction, another rockable lever under the first named lever, a stop lug on the under lever bearing against the upper lever and preventing movement of the same in a switch closing direction, a spring acting on the under lever to hold the lug in engagement with the upper lever and overcoming the action of said upper lever an expansible diaphragm engagin the under lever against the pressure diaphragm is expanded, a steam pipe connected to the diaphragm and communicating with the steam chamber of the boiler, means functioning independently of the steam-released lug for preventing the upper a switch closing direct e water in the boiler is at tion as long as and means allowing a predetermined level,

d said lever tilting means to function when the water in the boiler drops below said level.

4. A structure as in claim 1 in which the vessel is provided with a normally open airintake valve, arranged to automatically close when the vessel fills with water.

5. A structure as in claim 1, in which the vessel is provided with a normally open both when the vessel fills with water and independently with the presence of a certain In testimony whereof I affix my signature.

IRA E. SMITH.

and a pipe from the I of the spring when the d air-intake vent, and means to close the vent 

